Last updated: June 2001
The National Institute for Clinical Excellence (NICE) is a health authority established by the government to promote best practice in all areas of medical practice in the UK. Its unique status ensures that its recommendations and guidelines are generally highly regarded, for it is assumed that the advice they contain is based upon a comprehensive analysis of all the relevant literature by individuals experienced in the subject area. In reality, however, this may be far from the truth.
Recent guidelines on the use of debriding agents for 'difficult to heal surgical wounds' were based upon a systematic review undertaken by the NHS Centre for Reviews and Dissemination in the University of York. Unfortunately this review was seriously flawed in many areas and fell far short of the standard required of a publication intended to form the basis of national guidelines.
This article does not consider all the shortcomings of the report, but will highlight some of the most important issues. These suggest that the document was produced by individuals who, although highly skilled in health economics and methodological analysis, in the main had little understanding or detailed practical knowledge of the specific subject area.
From their initial literature review the authors selected 17 studies for analysis, several of which related to excised pilonidal sinus wounds left to heal by secondary intention. Whilst infected or dehisced wounds certainly present problems of wound healing, non-infected pilonidal sinus wounds healing by secondary intention normally do not. It is true that the healing process may take a number of weeks, but this does not necessarily mean that the wound is infected or 'hard to heal'. On the contrary, such wounds normally heal in a very predictable fashion, enabling Marks et al  to derive an equation to predict healing times based upon measurements of their initial size and depth. Unless they have become clinically infected or show no evidence of healing over an extended period, pilonidal sinus wounds should not have been included in this review.
Evidence for debridement activity involving other wound types was excluded from the review although there is little logic in this. There is no evidence that the slough or necrotic tissue encountered in surgical wounds is any different from that which develops in chronic wounds, or that the efficacy of different forms of debriding agents will vary between wound types. The balance of evidence actually suggests that the reverse is true, and therefore debridement techniques that are effective in one wound type will also be effective in another.
The primary outcome selected for the review was 'an objective measure of healing'. In a study that is claimed to relate to wound debridement, this decision must be challenged. The removal of slough and/or necrotic tissue from a wound represents a significant event in the management of that wound and should therefore be regarded as an important outcome measure in its own right in line with current clinical opinion. In the management of malignant wounds, where healing is considered unlikely, debridement may be performed to eliminate necrotic tissue that acts as a focus for infection or odour production. Alternatively, successful debridement may be followed by delayed primary closure or the application of a skin graft. The importance of debridement to practitioners has been demonstrated by the publication of numerous studies and reviews that describe the various techniques available for wounds of all types , , , , , , , , , .
Although each of the studies selected by the authors was scrutinised and analysed in considerable detail, they failed to take account of the two most important parameters. Specifically whether the wounds were truly 'hard to heal' and, even more importantly, if the studies in question provided hard evidence that the wounds contained any slough or necrotic tissue prior to treatment and therefore required any form of debridement.
Given the considerable emphasis in the report placed upon the need for all clinical papers to meet strict inclusion criteria, it is incomprehensible that publications could be included in a review of debriding agents that make no reference to these key points. This is particularly absurd when one considers that a well-conducted randomised control trial (RCT), which measured the removal of necrotic material from 500 dehisced, sloughy, abdominal wounds using an objective and scientifically validated computerised technique would have been rejected by the authors because it did not use healing time as the primary outcome measure.
Several of the selected studies referred to Silastic foam, a product that was discontinued some years ago, whilst others described the use of Debrisan beads, a dressing that is now hardly ever used in clinical practice. The authors' decision to consider only data obtained from RCTs and ignore information from other sources is also unfortunate, given the total lack of relevant studies.
Advancement in any branch of science, including medicine, depends upon an open mind, careful observation, and the ability or will to recognise an effect or outcome that is of value or is worthy of further examination. Whilst it is accepted that an RCT provides the most robust form of clinical evidence, in the absence of any relevant studies alternative types of evidence should be considered. Clinical assessments and small-scale evaluations involving hundreds if not thousands of patients with genuinely hard to heal surgical wounds with treatments such as vacuum assisted closure, hydrogels and sterile maggots must surely be worthy of serious consideration.
The National Institute for Clinical Excellence has a reputation for promoting best practice in all areas of medicine but on this occasion, by issuing guidelines based upon a seriously flawed report, it has fallen far short of this aim and as such its actions may delay progress in wound management for years to come.
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